Apparatus and method of cleaning film

ABSTRACT

An apparatus and method for removing dry contaminants, grease, oil, and mottle is disclosed. The apparatus comprises a pair of rollers, a pair of applicators secured to the rollers, a tank to hold a cleaning solution, and a pair of transfer rollers between the tank and the applicators, adapted to apply a cleaning solution to the applicator. A pair of electric stepping motors is utilized to drive the rollers, causing said rollers and applicators to rotate in opposite direction to one another. An oscillator, digital splitter, and a pair of translator drives are also employed to, in conjunction with the motors, to further cause the rollers and applicators to rotate in pulsed, 0.7 degree increments, at a rate of approximately 100 pulsed increments per second.

TECHNICAL FIELD

[0001] The present invention relates to an apparatus for cleaning film, and particularly relates to non-immersion film cleaning, removing both dry particles and oil mottle from film surfaces.

BACKGROUND ART

[0002] In the past, films used in creating motion pictures have been made from many different substances including cellulose nitrate, diacetate, triacetate and polyester. However, the unstable nature of cellulose nitrate, diacetate and triacetate necessitate the copying of films onto longer lasting film material such as polyester.

[0003] Nevertheless, every time film is handled or transported, it attracts contaminants, including, but not limited to: dust, fibres, hairs, insects, dirt, and oil mottle. Contaminants on the surface of the original film may lead to varied film base and emulsion scratches. They can also lead to spots and marks on the copy. Often, film is copied and/or converted in modern day converting facilities where the film is transferred at very high rates of speed and contaminants on the surface of the original film may not be noticed until the transfer is complete and the film is ready for viewing. At which point, the quality of the picture projected onto the screen from the film can become degraded to the point where entire reels of film are not suitable for commercial purposes. Thus, the removal of contaminants from film before transfer, copying or conversion has become an essential part of copying and converting process.

[0004] One of the first film cleaning methods developed is manually cleaning the film by hand. A lint free cloth is moistened with a chemical solvent, folded over the film and moved along the length of the film. This process is accelerated by using the rewind mode of a projection machine to run the film through the cloth while applying pressure by hand. Although this technique is still in use today by some private film collectors, there are obvious disadvantages to this method of cleaning film. This method poses hazards to the health of the user who is in direct contact with the chemical solvent and is slow and time consuming. This method is not practical for commercial purposes. Further, film can be permanently damaged if wound up while still wet or if the cleaning cloth is not changed often enough.

[0005] In the interest of speeding up the cleaning process, machines were developed that utilize the basic concept of the manual cleaning methods. For example, U.S. Patent to Henderson et al purports to teach an ultrasonic film cleaning apparatus. The invention describes a pair of cleaning cloth strips, between a pair of beds, which are positioned in such a way as to sandwich the film between them. Means are provided to wet the cloth strips with a solvent, while an ultrasonic device is positioned on each bed causing cavitation at the interface between the film and the associated cleaning cloth. The housing of the beds has a conduit that is received at the interior of the ultrasonic device. A feeding port conducts from the conduit to the bed, wetting the cleaning cloth in the process. The fluid is under pressure to be able to exit in a vertical upward direction, which is one of the greatest disadvantages to this invention. The pressurized solvent poses dangers to the user due to the high volatility of the solvent used.

[0006] In an effort to correct many of the problems and disadvantages of earlier cleaning methods, large solvent immersion cleaning devices have been developed. Although the dangers associated with pressurized volatile chemicals are eliminated, the solvent immersion cleaning devices still utilize toxic solvents such as methyl chloroform (1,1,1 trichloroethane), to clean the original film. The manufacture of methyl chloroform ceased as of Dec. 31, 1995. Immersion devices are large and sloppy and are often dangerous to the health of the users and to the environment. There are still immersion devices in existence which utilize other legal, but still toxic and odiferous solvents. Due to the large size of the immersion tanks and the space constraints of the users, immersion tanks are often set proximate to highly technical and very expensive film machinery which can be damaged by splashes or spills.

[0007] U.S. Pat. No. 4,244,078 to Hughes is one example of a type of solvent immersion cleaning device. In Hughes, a contaminated film is moved through a solvent bath by a reel mechanism. While in the solvent bath the film is subject to ultrasound for a more effective cleaning. After emerging from the bath a pair of spray nozzles direct high-pressure spray of solvent to remove the excess solution. The final traces of solvent are removed by a pair of air nozzles. A plurality of cooling coils condenses the solvent, collects it and disposes of it. In addition to the health risks associated with a tank full of solvent and the dangers it poses to nearby equipment, this invention fails to adequately clean the film. Dirt has the potential to be smeared into the film rather than be released.

[0008] Other examples of solvent immersion cleaning devices are U.S. Pat. Nos. 1,334,655 and 5,361,444. These patents purport to teach film-cleaning devices that have a pair of wick plates extending down into a cleaning agent. The contaminated film is pressed between the wick plates that are moistened by a chemical solvent by means of capillary action. The amount of cleaning agent supplied to the film can be altered by adjusting the pressure applied by the pressure plates. A uniform drying process can be easily recognized by drying streaks forming on the emulsion film. Some of the disadvantages of this device are the requirement of constant supervision to adjust the pressure of the plates as required, in addition to the health risks associated with having an open solvent tank in which the solvent is exposed. Further, the film cleaning is less efficient than some of the foregoing devices.

[0009] In response to many of the environmental and health concerns, as well as the other disadvantages to solvent immersion cleaning devices, many non-solvent or “dry” cleaning devices have been developed. These “dry” cleaning devices are less efficient than many of the solvent devices and fail to remove grease and oil mottle. One such device utilizes rotating elastomer rubber transfer rollers which directly contact the film removing only dry and unattached contaminants down to 1 micron in size. The rubber transfer rollers then contact a large rotating adhesive roller which removes the contaminants from them so they can continue to remove contaminants from the film. Another device utilizes particle transfer rollers (PTRs) made from an inert polyurethane with no adhesives, silicones or leachable plasticizers. The PTRs rotate and also remove only dry contaminants. One crucial disadvantage of “dry” cleaners is the increase in friction on the film. Friction is minimal in solvent or “wet” cleaning devices.

[0010] U.S. Pat. No. 5,713,102 to Schmitzer purports to teach an example of an apparatus for dry cleaning films. The apparatus is composed of a dry cleaning unit comprising an ionization unit, which includes an electrostatic discharge device and means for removing discharged particles from the film, a drive motor, a roller driven by the motor, a film take up reel and means for controlling the drive motor so tensile forces remains uniform. The friction created by this device can damage film. Continuos control and monitoring is thus required while dry cleaning film.

[0011] U.S. Pat. No. 5,423,104 to West also describes a dry cleaning apparatus for film. This patent shows a filmstrip cleaner apparatus that uses elastomeric particle transfer rollers for film cleaning, as described above. All of the disadvantages of dry cleaning are present in this invention.

[0012] Thus, it is clear that a device is needed that will clean grease and oil mottle as well as dry contaminants without damaging the original film and without utilizing immersion techniques or noxious substances that pose dangerous health and safety risks.

SUMMARY OF THE INVENTION

[0013] It is an object of the present invention to utilize particle transfer rollers to remove dry contaminants in combination with a non-immersion cleaning subassembly and buffers to further remove grease and oil mottle from film. These and other objects will be apparent from the specification that follows. In the preferred embodiment of this invention there is provided a sub-assembly for cleaning film, said sub-assembly comprising (a) at least one roller; (b) at least one applicator removably attached to said at least one roller; (c) at least one tank adapted to hold a cleaning solution; and (d) at least one transfer roller, disposed between said at least one tank and said at least one applicator, adapted to apply the cleaning solution to said at least one applicator.

[0014] Additionally, in the preferred embodiment, there is further provided an apparatus for cleaning film, which, in addition to the aforementioned subassembly, comprises (a) a first platter adapted to hold the film; (b) at least one guide member located between the first reel and the roller, and adapted to receive the film; (c) at least one particle transfer roller located between the first reel and the roller adapted to receive the film; (d) a second platter adapted to hold the film as it is transferred from the first platter; (e) at least one buffer located between the at least one tank and the second reel; (f) at least one particle transfer roller, located between the at least one buffer and the second platter, adapted to receive the film; and (g) at least one guide member located between the buffer and the second platter, adapted to receive the film.

BRIEF DESCRIPTION OF THE DRAWINGS

[0015]FIG. 1 is a perspective view of the preferred embodiment of the subject invention cleaning a thirty-five millimeter film.

[0016]FIG. 1A is a perspective view of the preferred embodiment of the subject invention cleaning a sixteen millimeter film.

[0017]FIG. 2 is an enlarged view of the upper portion of the preferred embodiment as of the subject invention, as depicted in FIG. 1.

[0018]FIG. 3 is an enlarged view of the non-immersion cleaning sub-assembly.

[0019]FIG. 4 is an enlarged view of the non-immersion cleaning sub-assembly with the applicators removed, showing the rollers and the transfer rollers within the solvent tanks.

[0020]FIG. 5 is an enlarged view of a transfer roller.

[0021]FIG. 6 is a flow chart showing the method used in the preferred embodiment to achieve the preferred pulsed rotation of the rollers and applicators.

[0022]FIG. 7 is a view of the back side of the upper portion of the subject invention.

BEST MODE FOR CARRYING OUT INVENTION

[0023] For the purpose of promoting an understanding of the present invention, reference will be made to an embodiment of a film cleaning apparatus as illustrated in the drawings. It will nevertheless be understood that no limitations of the scope of the invention is thereby intended by such alterations as changing (I) the geometry of the invention or any element of the invention (II) the placement of the various rollers, transfer rollers, particle transfer rollers and other elements, or (III) the quantity of each element. It is contemplated that such alterations and others of a similar nature would fall within the spirit and scope of the invention described herein. Some of the possible alterations are mentioned herein below.

[0024] With particular reference to the drawings, the reader should understand that like numerals in different figures refer to the same elements of the invention.

[0025] Referring now to the drawings, FIGS. 1 and 1A, which shows a preferred embodiment of the film cleaning apparatus 10 cleaning a 35-mm film and a 16 mm film, respectively. A film cleaning apparatus 10 includes a planar mounting surface 70 for mounting the components comprising the film cleaning apparatus . One of ordinary skill in the art will readily appreciate that the mounting surface 70 can either be a single unit large enough to include all of the chosen components or it can be any number of smaller units attached together.

[0026] The film cleaning apparatus 10 further includes a pair of film platters 12 and 12′ that act as a film feeding device and a film receiving device respectively.

[0027] In the preferred embodiment, the first film platter, 12 is removably attached to the uppermost section of the apparatus 10 and the second film platter, 12′, the takeup platter, is removably attached to the lowermost section of apparatus 10. It is conceivable and one of ordinary skill in the art would readily appreciate that the film platters 12 and 12′ could either be aligned horizontally or not aligned at all.

[0028] Film 14 is generally wrapped around a first film core 11 which is then removably attached to the first film platter 12. A second empty film core 11′, which receives the cleaned film is removably attached to the second film platter 12′.

[0029] To begin the film cleaning process, the film 14 is loaded onto the uppermost film platter 12. In the preferred embodiment, the film 14 is then guided to a particle transfer roller 16. One of ordinary skill in the art would readily recognize that the machine operator could lace the film 14 through the components of the cleaning apparatus 10 in any number of different ways.

[0030] In the preferred embodiment, all of the particle transfer rollers 16, 17, 19, 80, and 82 are the type manufactured and sold by San Lab Systems, Inc. The particle transfer rollers are capable of eliminating a large amount of dust, dirt and lint from film. One of ordinary skill in the art would readily recognize that the particle transfer rollers 16, 17, 19, 80 and 82 could be disbursed throughout the film cleaning apparatus 10 in any number of combinations From particle transfer roller 16, the film 14 is then guided around guide 18, in case of a 35-mm film, and guide 20, in case of a 16-mm film. One of ordinary skill in the art will readily appreciate that guides of various sizes may be used depending on the film size. Moreover, one of ordinary skill in the art will also recognize that guides may be eliminated all together. Subsequently, the film 14 is then guided through a series of particle transfer rollers 17, most preferably four particle transfer roller, such that the film moves alternately over and under the particle transfer rollers, before being placed in contact with the film cleaning applicator 32 However, one of ordinary skill in the art would readily appreciate that the film 14 need not alternate over and under the particle transfer rollers and that the number of particle rollers between the film platter and the film cleaner 30 could be zero (0) to an infinity. However, it is preferred that at least one particle transfer roller 16 or 17 be used to remove loose particles such as dust or lint before the film 14 reaches the film cleaner 30 to reduce the likelihood of scratching the film 14.

[0031] The film is then passed through a film cleaner 30, as shown in FIGS. 1, 1A, 2, 3, and 4, to clean grease and oil mottle. The film cleaner, most preferably, is comprised of a plurality of rollers 22, a plurality of applicators 32, a plurality of solvent tanks 34, a plurality of heaters 36, a plurality of level controllers 38, and a plurality of transfer rollers 40. However, one of ordinary skill in the art will readily appreciate that the number of each component comprising the film cleaner 30 may equal any number from one (1) to infinity. Additionally, the plurality of solvent tanks 34 house a reservoir of cleaning solution, most preferably hydronaptha.

[0032] As the film 14 is guided through the film cleaner 30, the film 14 is first placed in contact with a pair of applicators 32, as shown on FIGS. 1, 1A, 2 and 3, to remove grease, oil mottle and other residues. In the preferred embodiment, the film 14 is fed between and is contacted by the applicators 32 that are removably attached to the drive rollers 22. The drive rollers 22, which are attached to the mounting surface 70, rotate in pulses and are driven by a pair of electronic step motors 56. Each drive roller 22 is secured to a shaft of the corresponding electronic step motor 56.

[0033]FIG. 6 schematically represents the operation of the electronic step motor 56. As shown in FIG. 6, oscillator 50 generates pulsed electrical signal 58 which is delivered to splitter 52, via electrical cables (not shown) that separates signal 58 into two identical signals of the same frequency, which is identical to the frequency of the signal generated by oscillator 50. In the preferred embodiment, a 7406 hex driver is used as a digital splitter, and the oscillator is capable of generating electrical signals of varying frequencies. Oscillator 50 generates signals 58 with frequencies varying between 10 Hz and 1 KHz, at 500 pulses per second. Most preferably, oscillator 50 generates a 100 Hz signal. Signals 58 emanating from digital splitter 52 are being transmitted to translator drives 54 at 500 pulses per minute. Signal 58 then enters translator drive 54 which translates signal 58 into pulsed signals 59. Pulsed signals 59 are received by electronic step motors 56 that, in turn, drive rollers 22. In the preferred embodiment, the translator drives 54 are of the type manufactured and sold by Warner Electric under the Slo-Syn® trademark, Model No. SS20000MD4. The electronic step motors 56, most preferably also are the type manufactured and sold by Warner Electric under the trademark Slo-Syn®, Model KML061 F05. The electronic step motors are set to rotate in opposite directions, and, rotate rollers 22 or 0.35 or 0.7 degree pulsed increments, at 100 pulses per second. In a preferred embodiment, rotation of 0.7 degree per pulse increment is achieved. This causes an upward vibration that moves the film downward 14 through roller 22 and applicators 32.

[0034] Located beneath the first pair of rollers 22 are solvent tanks 34 that hold a chemical solvent, most preferably, hydronaphtha. Heaters 36 located directly underneath each solvent tank 34, heat the cleaning solution. In the preferred embodiment, the Hydronaphtha is kept at a temperature of approximately 26-30° C. (78-86° F.). One of ordinary skill in the art will readily recognize that other cleaning solutions such as Isopropanol and HFE 8200 3M® can be used in place of the Hydro treated Naptha and that different solutions may not need to be heated.

[0035] As shown in FIG. 2A, the cleaning solution is stored in an inverted bottle 60 located on the apparatus 10 and is gravity fed into the solvent tank 34 through plastic tubing 62, as shown in FIG. 2A. In a preferred embodiment, the solvent is maintained at a constant level within the solvent tanks 34. Each tank 34 is self-leveling so that when the level of the solvent drops below a certain level, an air bubble is expelled causing the inverted bottle 60 to release more solvent. In a preferred embodiment the solvent is maintained at a level corresponding to one half of the capacity of the solvent tank. A pair of hose adaptors 38 located on the front of the solvent tanks 34 allows used to determine the level of the solvent within the solvent tank 34.

[0036] Within each solvent tank 34 is a transfer roller 40, as shown in FIG. 4. FIG. 5 depicts the transfer roller 40 which is comprised of a metal cylinder 42 with one continuous helical groove 44 cut into the outer surface, a spacer 46, and a shaft 48. The continuous helical groove 44 covers the entire length of the metal cylinder 42. In the preferred embodiment, the transfer rollers 40 are set inside the solvent tanks 34 such that the transfer rollers 40 are partially submerged in the cleaning solution. The transfer rollers 40 are caused to rotate at a set speed by a gear motor 68. In the preferred embodiment a Baldor motor, Model No. GP323111 is used. Also in the preferred embodiment, transfer rollers 40 rotate at approximately 60 rpm. The rotation in combination with the helical groove 44 allows the transfer roller 40 to act like a wick, drawing the chemical solvent up out of the solvent tank 34 and on the applicators 32. The applicators 32, which are rotably pulsed along the rollers 22 as detailed above, then transfer the chemical solvent to film 14 in a gentle scrubbing manner.

[0037] The film 14 is then passed through two pairs of rollers 22 with buffers 24 removably attached to each individual roller 22 as shown in FIG. 1. The two pairs of rotary buffers 22 dry and polish the film 14. Moreover, the rollers 22 are caused to rotate at a high rate of speed by motors 66 located on the apparatus 10. Specifically, the right rollers 22 rotate clockwise and the left rollers 22 rotate counter-clockwise.

[0038] The film is then guided through a second series of particle transfer rollers 19, 80 and 82. This second series finalizes the cleaning process. In the preferred embodiment, the second series of particle transfer rollers 19, 80 and 82 is composed of seven (7) particle transfer rollers 19, 80 and 82. Once more, one of ordinary skill in the art can readily appreciate that the number of particle transfer rollers 19, 80 and 82 in the second series of particle rollers can vary from zero (0) to infinity and the order in which the film 14 is passed through them can vary upon the preference of the operator. After passing through the second series of particle transfer rollers 19, 80 and 82, film 14 is guided over a second sixteen millimeter guide 20 or thirty-five millimeter guide 18 depending on the size of the film. One of ordinary skill in the art will readily appreciate that guides of various sizes may be used depending on the film size. Moreover, one of ordinary skill in the art will also recognize that guides may be eliminated all together. Finally, the film 14 is connected to a second film core 11′, which is removably secured to the second removable film platter 12′ located on the bottommost section of the front side of the apparatus 10.

[0039] One of ordinary skill in the art will readily recognize that the take up of the film by the second platter 12′ can be facilitated by the use of a motor that is operatively connected to the second film platter 12′. Specifically, it is readily apparent to one of ordinary skill in the art that a motor attached to the second film platter 12′ would draw the film 14 from the first film platter 12 through the various components of apparatus 10 and into the second film platter 12′.

[0040] Although the best mode contemplated for carrying out the present invention has been herein shown and described, it will be apparent that modifications and variations may be made without departing from what is regarded as the subject matter of the invention. 

What is claimed:
 1. A film cleaning apparatus comprising: a film feeding device; a film cleaner, adapted to receive film from said film feeding device, having, at least one roller; at least one applicator removably attached to said at least one roller; at least one solvent tank adjacent to said at least one applicator having at least one transfer roller to transfer solvent, said transfer roller having a continuous helical groove and in rotating contact with said at least one applicator; a film buffer adapted to receive film from said film cleaner having at least one buffing roller having a buffer removably attached to said buffing roller; a film receiving device adapted to receive film from said film buffer.
 2. A film cleaning apparatus according to claim 1 further comprising at least one heater in operative contact with said at least one solvent tank.
 3. A film cleaning apparatus according to claim 1 further comprising at least one solvent storage reservoir modified to deliver solvent to said at least one solvent tank.
 4. A film cleaning apparatus according to claim 3 further comprising a controller to control the flow of said solvent from said at least one storage reservoir.
 5. A film cleaning apparatus according to claim 1 wherein said solvent is hydronaptha.
 6. A film cleaning apparatus comprising: a film feeding device; at least one particle transfer device adapted to receive said film from said film feeding device a film cleaner, adapted to receive film from said at least one particle transfer roller, having, at least one roller; at least one applicator removably attached to said at least one roller; at least one solvent tank adjacent to said at least one applicator having at least one transfer roller to transfer solvent, said transfer roller having a continuous helical groove and in rotating contact with said at least one applicator; a film buffer adapted to receive film from said film cleaner having at least one buffing roller having a buffer removably attached to said buffing roller; a film receiving device adapted to receive film from said film buffer.
 7. A film cleaning apparatus according to claim 6 further comprising at least one heater in operative contact with said at least one solvent tank.
 8. A film cleaning apparatus according to claim 6 further comprising at least one solvent storage reservoir modified to deliver solvent to said at least one solvent tank.
 9. A film cleaning apparatus according to claim 8 further comprising a controller to control the flow of said solvent from said at least one storage reservoir.
 10. A film cleaning apparatus according to claim 6 wherein said solvent is hydronaptha.
 11. A film cleaning apparatus comprising: a film feeding device; at least one particle transfer device adapted to receive said film from said film feeding device; at least one film guide to channel said film from said at least one particle transfer device; a film cleaner, adapted to receive film from said at least one film guide, having, at least one roller; at least one applicator removably attached to said at least one roller; at least one solvent tank adjacent to said at least one applicator having at least one transfer roller to transfer solvent, said transfer roller having a continuous helical groove and in rotating contact with said at least one applicator; at least one film buffer adapted to receive film from said film cleaner having at least one buffing roller having a buffer removably attached to said at least one buffing roller; a film receiving device adapted to receive film from said film buffer.
 12. A film cleaning apparatus according to claim 11 further comprising at least one heater in operative contact with said at least one solvent tank.
 13. A film cleaning apparatus according to claim 11 further comprising at least one solvent storage reservoir modified to deliver solvent to said at least one solvent tank.
 14. A film cleaning apparatus according to claim 13 further comprising a controller to control the flow of said solvent from said at least one storage reservoir.
 15. A film cleaning apparatus according to claim 11 wherein said solvent is hydronaptha.
 16. A film cleaning apparatus comprising: a film feeding device; at least one particle transfer device adapted to receive said film from said film feeding device; at least one film guide to channel said film from said at least one particle transfer device; a second at least one particle transfer device adapted to receive said film from said film guide; a film cleaner, adapted to receive film from said second at least one particle transfer device, having, at least one roller; at least one applicator removably attached to said at least one roller; at least one solvent tank adjacent to said at least one applicator having at least one transfer roller to transfer solvent, said transfer roller having a continuous helical groove and in rotating contact with said at least one applicator; at least one film buffer adapted to receive film from said film cleaner having at least one buffing roller having a buffer removably attached to said at least one buffing roller; at least one particle transfer device adapted to receive said film from said at least one film buffer; a film receiving device adapted to receive film from said film buffer.
 17. A film cleaning apparatus according to claim 16 further comprising at least one heater in operative contact with said at least one solvent tank.
 18. A film cleaning apparatus according to claim 16 further comprising at least one solvent storage reservoir modified to deliver solvent to said at least one solvent tank.
 19. A film cleaning apparatus according to claim 18 further comprising a controller to control the flow of said solvent from said at least one storage reservoir.
 20. A film cleaning apparatus according to claim 16 wherein said solvent is hydronaptha.
 21. A film cleaner comprising: at least one roller; at least one applicator removably attached to said at least one roller; at least one solvent tank adjacent to said at least one applicator having at least one transfer roller to transfer solvent, said transfer roller having a continuous helical groove and in rotating contact with said at least one applicator.
 22. A film cleaner according to claim 21 further comprising at least one heater in operative contact with said at least one solvent tank.
 23. A film cleaner according to claim 21 further comprising at least one solvent storage reservoir modified to deliver solvent to said at least one solvent tank.
 24. A film cleaner according to claim 23 further comprising a controller to control the flow of said solvent from said at least one storage reservoir.
 25. A film cleaner according to claim 21 wherein said solvent is hydronaptha.
 26. A film cleaner comprising: at least one roller at least one applicator removably attached to said at least one roller; at least one solvent tank adjacent to said at least one applicator having at least one transfer roller to transfer solvent, said transfer roller having a continuous helical groove and in rotating contact with said at least one applicator; a film buffer adapted to receive film from said film cleaner having at least one buffing roller having a buffer removably attached to said at least one buffing roller.
 27. A film cleaner according to claim 26 further comprising at least one heater in operative contact with said at least one solvent tank.
 28. A film cleaner according to claim 26 further comprising at least one solvent storage reservoir modified to deliver solvent to said at least one solvent tank.
 29. A film cleaner according to claim 28 further comprising a controller to control the flow of said solvent from said at least one storage reservoir.
 30. A film cleaner according to claim 26 wherein said solvent is hydronaptha. 